Class 10 Science - Chapter Sources of Energy NCERT Solutions | What are the limitations of extracting e

Can any source of energy be pollution-free? Why or why not?

What are the limitations of the energy that can be obtained from the oceans?

If you could use any source of energy for heating your food, which one would you use and why?

On what basis would you classify energy sources as

(a) renewable and non-renewable?
(b) exhaustible and inexhaustible?

Are the options given in (a) and (b) the same?

What is a good source of energy?

Hydrogen has been used as a rocket fuel. Would you consider it a cleaner fuel than CNG? Why or why not?

Which of the following is not an example of a bio-mass energy source?

      (a) wood                     (b) gobar-gas
      (c) nuclear energy      (d) coal

What are the disadvantages of fossil fuels?

Give the names of two energy sources that you would consider to be exhaustible. Give reasons for your choices.

Name two energy sources that you would consider to be renewable. Give reasons for your choices.

Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

What are trophic levels? Give an example of a food chain and state the different trophic levels in it.

What changes can you make in your habits to become more environment-friendly?

What is the difference between a reflex action and walking?

What is the importance of DNA copying in reproduction?

If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?

Why should a magnesium ribbon be cleared before burning in air?

Define the principal focus of a concave mirror.

You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?

Let the resistance of an electrical component remains constant while the potential difference across the two ends of the component decreases to half of its former value. What change will occur in the current through it?

Find out about the traditional systems of water harvesting/management in your region.

The device used for producing electric current is called a

(a) generator.
(b) galvanometer.
(c) ammeter.
(d) motor.

Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).

Metal compound A reacts with dilute hydrochloric acid to produce effervescence. The gas evolved extinguishes a burning candle. Write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride.

How are fats digested in our bodies? Where does this process take place?

How do Mendel’s experiments show that traits may be dominant or recessive?

Samples of four metals A, B, C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows.

Plaster of Paris should be stored in a moisture-proof container. Explain why?

How would these advantages differ from the advantages of using a long-term perspective in managing our resources?